You'd have to be insane to do a spinoff of a book that doesn't even have a publication date yet -- wouldn't you?

Not if it's the sequel to "The Da Vinci Code," Dan Burstein says.

Burstein is a publishing entrepreneur with a day job: He's the founder of a New York-based venture capital firm. Lately he's been on the road promoting "Secrets of the Widow's Son," which promises to prep readers for "Da Vinci" author Dan Brown's next venture into the world of secret societies, conspiracy theories, myths and alternative history.

All that's known about the still-unscheduled Brown book is that when it's finally published -- perhaps in late 2006 or 2007 -- it will involve the Freemasons, will be set at least partly in Washington and will be called "The Solomon Key." That was enough for Burstein.

And why not?

He'd already made a killing with last year's "Secrets of the Code: The Unauthorized Guide to the Mysteries Behind the Da Vinci Code" -- of which there are well over a million copies in print.

Burstein says he got hooked on "Da Vinci" in June 2003, three months after Brown's religio-historical thriller was published. (Thirty-six million hardback copies are now in print worldwide, according to Brown's publisher, Doubleday.) He shelled out hundreds of dollars for books related to Brown's narrative, in which the Gnostic Gospels and Mary Magdalene figure heavily, and started thinking about a guidebook that could help readers separate fact from fiction.

He and a friend started a small company, Squibnocket Partners, to pull "Secrets of the Code" together. They made contact with Barnes & Noble, which signaled significant interest. They signed up more than 40 contributors (with Burstein serving as editor) and by May 2004 the anthology was a New York Times bestseller. Later came a guide to an earlier Brown book, "Angels and Demons."

Ah, but those books exist! How can you do a guide to a book that isn't written?

One of Burstein's team, reporter David Shugarts, supplied the answer by checking out a rumor that there was a code embedded in the dust jacket flaps of "The Da Vinci Code." Sure enough, some letters on the flaps were in a slightly bolder face and spelled out "Is there no hope for the widow's son?" Researching that phrase led Shugarts first to the history of the Mormon church and eventually -- the details are too complex to get into here -- to a predicted Washington/Freemason backdrop for Brown's next book.

Brown later confirmed as much in a rare public appearance.

So if you're truly Brown-obsessed -- or if you're just dying to read about the conjunction of Freemasonry, the Founding Fathers and the nation's capital -- "Secrets of the Widow's Son," which Burstein commissioned Shugarts to write, is there for you.

But for the publisher, there's more to it than that. Odds are the next Dan Brown work will be one of the biggest sellers ever -- and who do you think will be ideally positioned to rush a true guide into print? "We intend to do a whole 'Secrets of the Solomon Key,' " says Burstein, laughing, "once we can read 'The Solomon Key.' "

He's far from the only one piggybacking on Dan Brown. By now there are a couple dozen books with such titles as "Da Vinci Decoded" and "The Da Vinci Hoax" that serve as guides to or refutations of Brown's megahit. And there's even another preview title -- "The Guide to Dan Brown's 'The Solomon Key,' " by Greg Taylor -- though it lags behind "Widow's Son" in Amazon sales rank.

Burstein isn't losing sleep about competition. "People are so interested," he says.

The Soul of an Old War

"Just Another Soldier." "My War." "I Am My Brother's Keeper." "One Bullet Away." "Love My Rifle More Than You." Seems like publishers are churning out first-person war stories almost as fast as the authors' tours of duty in Afghanistan and Iraq are up. All, no doubt, offer valuable perspectives. Still: There's something to be said for a military memoir that wasn't lobbed into print like a hand grenade.

Take Tracy Kidder's "My Detachment," which took 36 years to make its way onto the printed page.

Kidder is a Pulitzer Prize-winning author of elegant nonfiction narratives built on immersive reporting, among them "The Soul of a New Machine" and "Mountains Beyond Mountains." But "My Detachment" has its roots in an attempt at fiction. When he got home from Vietnam, in 1969, he started a novel in which he imagined what it would have been like to lead a platoon in combat instead of what he actually did, which was to command a detachment of enlisted men doing communications intelligence work behind the lines.

Thirty-three publishers rejected it. Kidder burned his copies of the manuscript and gave up fiction writing for good. Nonfiction, he says, "just seemed to me something I could do."

Still, he wanted to write about Vietnam. He started a memoir in 1985 but had a hard time controlling its tone. The problem: He was trying to deny any connection between his mature self and the immature twenty-something who'd stepped off a plane in the midday Bien Hoa heat and into a command for which he was in no way prepared.

"I had gone to training camps for over a year and learned to avoid venereal disease and march and make my bed and fire weapons," Kidder writes, "but I had never received a single instruction on how to handle troops." What do you do when a soldier you're supposed to be commanding expresses displeasure with your leadership style and announces calmly: "We can shoot you any time we want, Lieutenant"?

Lt. Kidder had no clue. Nor could he have guessed that, a couple of decades later, that soldier would track him down, buy him lunch and explain why Kidder's own men had set fire to his latrine.

Why dredge up memories that still make him wince? Well, he's glad to have them out in the open where they can no longer ambush him. This kind of candor has a side benefit, too: As his friend and editor Richard Todd once pointed out, no one is likely to accuse Kidder of falsifying his experience "because there's never been a book about a young man at war who's been turned down by a prostitute."

Kidder does more than evoke his own embarrassments, however. He's drawn a classic portrait of a confused young man caught up in a dishonorable war. Take the scene in which an artillery captain reports how many Viet Cong his men have killed in a recent engagement.

Wait, says the colonel in charge: That's a village you're talking about. So what you mean is two Viet Cong and 73 women and children. Report it that way next time.

"I loved that man. He was honest," Kidder says.

The Style of 'Elements'

Illustrator Maira Kalman was an English major, but "to my chagrin," she says, she had never encountered William Strunk Jr. and E.B. White's venerable good-writing manual, "The Elements of Style."

Then she picked up a copy at a yard sale and decided she simply had to illustrate it.

It might seem a quixotic pairing. Kalman is a hip children's book illustrator, fabric designer and frequent contributor to the New Yorker. "Elements" is a textbook on the distinctly unhip topic of grammar and usage.

Ah, but "it's really a work of literature, not just a grammar book," Kalman says. She was knocked out, in particular, by the quirkily humorous phrases and sentences the authors employed to illustrate their writing rules.

With the blessing of the Strunk and White estates, she sold her idea to the Penguin Press. She circled hundreds of phrases she loved, narrowed the list down and started sketching. The results are quirkily humorous in their own right.

"Well, Susan, this is a fine mess you are in," write Strunk and White to demonstrate the proper punctuation of a name or a title in direct address. Kalman gives us a sad-eyed basset hound staring reproachfully from a pink background.

"His first thought on getting out of bed -- if he had any thought at all -- was to get back in again," the authors write to show the correct use of dashes. Kalman paints a young man in striped pajamas, not ready to face the day.

Does "The Elements of Style" really need illustrations? Of course not. The text-only version has been selling steadily for nearly half a century (the paperback was No. 89 on Amazon yesterday).

But if art draws new readers to Strunk and White's little gem, says Penguin Press's president and publisher, Ann Godoff, well, "that's the Lord's work for an editor."

Publisher Dan Burstein has gotten a jump on the "Da Vinci Code" author's next book.

Two of Maira Kalman's drawings for "The Elements of Style," the venerable manual of grammar and usage. They illustrate sentences that use the dash and the comma.

Tracy Kidder: Better 36 years late than . . .